@ch0si We know for certain that she used Sasamoto for his job, making him delete personal information about her from the system. Maybe she needs him to do something else related to his job? Or maybe there's no reason besides keeping the story going and I'm reading too much into it.
@MagiciansBlack forgot about that, thanks for the reminder. Yeah, i remember in ch 7 she washing her hands which full of blood. Maybe she's an assassin / something that needs her personal information access through sasamoto.